1. Field of the Invention
The present invention relates generally to processing of waste materials, and more particularly to processes and systems for treating organic waste materials to form a compost product.
2. Description of the Prior Art
Anaerobic digestion and composting processes have co-existed for many years as disposal alternatives for organic waste materials. Such materials include agricultural materials, “green” wastes, and pre- and post-consumer wastes. The primary objective of anaerobic digestion is the production of a mixture of hydrocarbon gases (“biogas”), which may be utilized as an energy source to generate electricity and/or heat. Any solid material remaining at the completion of the anaerobic digestion process is typically disposed of by conventional methods, such as transferring the material to a landfill. In contrast, composting processes focus on the production of a solid product that may be employed as a soil amendment.
Because of the high capital costs associated with anaerobic digestion equipment, composting has become the dominant method in the United States for the management and re-use of organic waste materials generated in rural and suburban settings. The growing use of composting as a preferred alternative to disposal of organic waste material has made some common environmental problems apparent. These problems include emissions of noxious gases and ozone pre-cursors, runoff from the compost facility, and high energy consumption during material processing. These problems may become particularly acute if the organic waste material contains large amounts of food waste or other high moisture content waste. Commercial-scale composting is also subject to a variety of financial considerations, including capital investment related to accommodating peak seasonal feedstock deliveries, compost process time, and controlling the timing of compost production to match the seasonal demand of the agricultural industry and other compost buyers.
It is therefore an objective of the invention to provide a process and system for treating organic waste materials that avoids or reduces the aforementioned environmental problems and addresses the financial considerations in an economically advantageous manner.